NAND flash memory, as well as other types of non-volatile memories (“NVMs”), are commonly used for mass storage. For example, consumer electronics such as portable media players often include flash memory to store music, videos, and other media.
A NVM can include multiple index pages to provide mappings between logical addresses and physical addresses. In some cases, mapping information corresponding to the most recently written user data is stored in the volatile memory of the device in order to provide faster readout. Periodically, this mapping information can be flushed out from the volatile memory to the index pages of the NVM to provide for longer-term storage of the information.
When an electronic device having a NVM shuts down cleanly, information stored in the index pages can be used directly to reconstruct the logical-to-physical mapping in volatile memory. However, when an electronic device shuts down uncleanly, at least some of the index pages may be outdated because the device may not have fully flushed out the most recent mapping information to the index pages. Consequently, the device may need to scan the entire NVM in order to reconstruct the logical-to-physical mapping in volatile memory. This process may be costly from a time perspective.